ODBC (DSN Less) connection/install problems 5.02.06

[David Ford]

Hi,
I have spent weeks developing an application using DSN-less connection to MySQL on our web server (using Access forms - as its an easy re-distribute)

I developed on a DELL Windows 7 Laptop x64, and with the 64 bit MySQL driver had no problems... Connection String was ...

DRIVER={MySQL ODBC 5.2 Unicode Driver};SERVER=xxx.xxx.xxx.xxx;Port=3306; DATABASE=xxxxxxx;UID=xxxxxxx;PASSWORD=xxxxxxx;Option=3;

I have installed the SAME 64 bit driver from the same MSI I downloaded on two identical DELL machines (the machines were all ordered together)
After struggling through the install errors ...
...copying msvcr100 (which never occured previously)
...trying to work out why they don't appear in the ODBC driver (either 32bit in system32 or 64bit in SysWow64)

I can finally create & test UserDSN's successfully on the problem laptops.

However, when I open the Application on the 2nd & 3rd machines, I still get the DATA SOURCE NAME NOT FOUND AND NO DEFAULT DRIVER SPECIFIED error.

The connection string is hard-coded into the application file, then copied to all machines. (Please don't suggest I copied the wrong file) Why does this driver not work reliably as intended ?

I cannot find any further ideas on the support pages - what steps can I take to fix the problem installs ? This MUST be fixed, there is weeks of work behind the project.